Torque Receiving Assembly, Photosensitive Drum And Process Cartridge

ABSTRACT

A torque receiving assembly, a photosensitive drum and a process cartridge having such torque receiving assembly. The torque receiving assembly having a body having an axis and having an accommodating chamber; a driven shaft disposed coaxially with the body, the driven shaft including a guide stem and a coupling head provided at one axial end of the guide stem, the guide stem having a pair of output arms which extend outwardly in a radial direction, the coupling head having a plurality of projections; wherein a pair of input arms are provided at an inner wall of the accommodating chamber and configured for abutting with the output arms; the guide stem is movable in the axial direction relative to the body, the torque receiving assembly further has a distance-limiting mechanism that defines a maximum distance the driven shaft is able to move relative to the body in the axis direction. The photosensitive drum and process cartridge according to the present invention both include the torque receiving assembly.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/340,007 which was filed with the U.S. Patent and TrademarkOffice on Jul. 24, 2014, which claims priority from Chinese patentapplication No. 201310316731.2 filed on Jul. 25, 2013. Both applicationsare hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a torque receiving assembly fortransmitting rotational force, and a photosensitive drum and a processcartridge to which said torque receiving assembly is mounted as acomponent.

DESCRIPTION OF RELATED ART

FIG. 1 illustrates an image forming process for a laser printer in whicha process cartridge works as a core element. First, an outer peripheralsurface of a photosensitive drum 101 is electrically charged uniformlyby a charge roller 102, and a laser scanner 103 radiates a modulatedlaser beam 104 containing image information to the outer peripheralsurface of the drum 101. Then an unevenly distribution of electrostaticcharge, i.e. an electrostatic latent image corresponding to an image tobe printed, is formed on the outer peripheral surface of the drum afterirradiated by the laser beam. Subsequently, a developing agent such astoner conveyed by a developing roller 105 which has been regularized bya doctor blade 113, is transmitting to the outer peripheral surface ofthe photosensitive drum and covering the aforementioned latent image,and converting it to a visual image which can be seen by eyes. Withrotation of the photosensitive drum 101, the visual image moves to aposition where a transfer roller is provided. By applying a voltagecarried by the transfer roller 107, the toner is transferred onto anouter surface of a recording medium 108 such as paper, then the toner isheaded and pressed by a heating roller 111 and a pressing roller 112,and penetrated into the fiber layer of the recording medium 108, so thevisual image formed by toner is permanently fixed on the recordingmedium 108. After the visual image on the photosensitive drum 101 istransferred by the transfer roller 107, the toner remaining on thephotosensitive drum 101 is cleaned by a cleaning blade 110 and conveyedinto a waste toner container, and the electrostatic on the surface ofthe photosensitive drum is eliminated by an eliminating device, then thephotosensitive drum is recovered to a standby state without electric andtoner. Thus, a basic image forming process is completed. The processoperating in cycles repeatedly will result in forming a printed imageneeded by a user.

The rotational force, i.e. torque, generated by the aforementioned laserprinter, is transmitting to the photosensitive drum 101 by a driveshaft, and then bringing the process cartridge into a working state. InUS patent application publication NO. 2008/0152388A1, a processcartridge having a torque receiving assembly comprising a ball-typeuniversal joint provided on one end of its drum, is disclosed. Thisball-type universal joint tends to be undesirably detachable from theflange, especially during transportation, and this phenomenon willresult in the ball-type universal joint losing its transmitting functionor working stability.

SUMMARY OF THE INVENTION

To solve the easily detachment problem of the ball-type universal joint,a principal object of the present invention is to provide a torquereceiving assembly which is reliable and stable during rotational forcetransmitting.

Another object of the present invention is to provide a photosensitivedrum using the aforementioned torque receiving assembly. Thephotosensitive drum comprising such torque receiving assembly isreliable and stable during rotational force transmitting.

A further object of the present invention is to provide a processcartridge for a laser printer in which the aforementioned torquereceiving assembly mounted as a component. The process cartridgecomprising such torque receiving assembly can be mounting smoothly, andbe reliable and stable during rotational force transmitting.

A torque receiving assembly is provided by the present invention. Thetorque receiving assembly comprises: a body having an axis and having anaccommodating chamber; a driven shaft disposed coaxially with said body,the driven shaft including a guide stem and a coupling head provided atone axial end of said guide stem, the guide stem having at least oneoutput arm which extends outwardly in a radial direction, the couplinghead having a plurality of projections; wherein at least one input armis provided at an inner wall of the accommodating chamber and configuredfor abutting with the output arm; the guide stem is movable in the axialdirection relative to the body, the torque receiving assembly furthercomprises a distance-limiting mechanism that defines a maximum distancethe driven shaft is able to move relative to the body in the axisdirection.

Preferably, in the torque receiving assembly, the accommodating chamberis a cylindrical chamber provided coaxially with the body.

Preferably, in the torque receiving assembly, the accommodating chamberis a regular polygon chamber provided coaxially with the body.

Preferably, in the torque receiving assembly, a recess recessinginwardly in the axial direction of the guide stem is provided at acentral portion of the outer end wall of the coupling head.

Preferably, in the torque receiving assembly, the recess has a sphericalshape. The center of the recess is provided on the axial line of theguide stem.

Preferably, in the torque receiving assembly, the recess has a polygoncross section. The center of a phantom circle connecting all anglepoints of the polygon is provided on the axis of the guide stem.

Preferably, in the torque receiving assembly, a portion around therecess of the end wall of the coupling head is curved and projectingaway from the guide stem in the axial direction of the guide stem.

Preferably, in the torque receiving assembly, the body includes aguiding hole capable of guiding the guide stem along the axis direction.The distance-limiting mechanism comprises a retaining cover and anurging spring. The retaining cover is fixed to an open end of theaccommodating chamber to retain part of the driven shaft in theaccommodating chamber. The urging spring is interposed between theoutput arms and a bottom wall of the accommodating chamber for urgingthe driven shaft outwardly in the axis direction.

Preferably, in the torque receiving assembly, the body includes aguiding hole capable of guiding the guide stem. The distance-limitingmechanism comprises a retaining cover and a tension spring. Theretaining cover is fixed to an open end of the accommodating chamber toretain part of the driven shaft in the accommodating chamber. Thetension spring is disposed outside of the accommodating chamber with oneend connected to an end of the guide stem and the other end positionedagainst an end wall around the guiding hole of the body.

Preferably, in the torque receiving assembly, the distance-limitingmechanism comprises a retaining cover and an urging spring. Theretaining cover is mounted on an open end of the accommodating chamberto retain the driven shaft. The urging spring is interposed between theoutput arms and a bottom wall of the accommodating chamber for urgingthe driven shaft outwardly in the axis direction. A gap is providedbetween an end of the driven shaft and the bottom wall when the drivenshaft is at a farthest position from the bottom wall. The gap has anaxial length that is longer than an axial length of the projection.

Preferably, in the torque receiving assembly, the distance-limitingmechanism comprises a retaining cover, a first magnet and a secondmagnet, the retaining cover is mounted on an open end of theaccommodating chamber to retain the driven shaft, the first magnet isfixed to an end of the guide stem that is opposite the coupling head,the second magnet is fixed on a bottom wall of the accommodating chamberwith a gap away from the first magnet, the first and second magnets aredisposed such that each has a same polarity facing each other, the gaphas an axial length that is longer than an axial length of theprojection.

Preferably, in the torque receiving assembly, the distance-limitingmechanism comprises a retaining cover, a first magnet and a secondmagnet. The retaining cover is mounted on an open end of theaccommodating chamber to retain the driven shaft. The first magnet isfixed to an end of the guide stem that is opposite to the coupling head.The second magnet is fixed on an bottom wall of the accommodatingchamber with a gap away from the first magnet. The first and secondmagnets are disposed such that each has a same polarity facing eachother. The gap has a axial length that is longer than an axial length ofthe projection.

Preferably, in the torque receiving assembly, the distance between anouter wall of the projection in a radial direction away from the axialline of the guide stem and the extended axial line of the guide stemreduces gradually along the extending direction of the projection.

Preferably, in the torque receiving assembly, the projection has arectangle shape in a cross section parallel to the axial direction ofthe guide stem.

Preferably, in the torque receiving assembly, the projection has a stepat the outer wall of the guide stem in a cross section parallel to theaxial direction of the guide stem. The distance between the step and theextended axial line of the guide stem is tapering in the extendingdirection of the projection.

Preferably, in the torque receiving assembly, the projection has atrapezoid shape in a cross section parallel to the axial direction ofthe guide stem, and the bevel edge of the trapezoid is out of the guidestem in the radial direction. The distance between the bevel edge andthe extended axial line of the guide stem is tapering in the extendingdirection of the projection away from the guide stem.

Preferably, in the torque receiving assembly the driven shaft includes athrough-hole substantially perpendicular to the axis direction of theshaft. A pin, preferably made of metal, is slidably received in thethrough-hole, and wherein ends of the pin comprise output arms.

A photosensitive drum is provided based on a first object of the presentinvention. The drum comprises a body having an axis and having anaccommodating chamber; a driven shaft disposed coaxially with the body,the driven shaft including a guide stem and a coupling head provided atone axial end of the guide stem, the guide stem having a pair of outputarms which extend outwardly in a radial direction, and the coupling headhaving a plurality of projections. A pair of input arms are provided atan inner wall of the accommodating chamber. The input arms areconfigured for abutting with the output arms. The guide stem is movablein the axial direction relative to the body. The torque receivingassembly further comprises a distance-limiting mechanism that defines amaximum distance the driven shaft is able to move relative to the bodyin the axis direction.

Optimized, in the photosensitive drum the accommodating chamber is acylindrical chamber provided coaxially with the body.

Optimized, in the photosensitive drum the accommodating chamber of thetorque receiving assembly is a regular polygon chamber providedcoaxially with the body.

Optimized, in the photosensitive drum a recess recessing inwardly in theaxial direction of the guide stem is provided at central portion of theouter end wall of the coupling head of the torque receiving assembly.

Optimized, in the photosensitive drum the recess of the torque receivingassembly has a spherical shape. The center of the recess is provided onthe axial line of the guide stem.

Optimized, in the photosensitive drum the outer wall of the recess has apolygon shape in a cross section vertical to the axial direction of theguide stem. The center of a phantom circle connecting all angle pointsof the polygon is provided on the axis of the guide stem.

Optimized, in the photosensitive drum the portion around the recess ofthe end wall of the coupling head is curved and projecting away from theguide stem in the longitude direction of the guide stem.

Optimized, in the photosensitive drum the body includes a guiding holecapable of guiding the guide stem along the axis direction. Thedistance-limiting mechanism comprises a retaining cover and an urgingspring. The retaining cover is fixed to an open end of the accommodatingchamber to retain part of the driven shaft in the accommodating chamber.The urging spring is interposed between the output arms and a bottomwall of the accommodating chamber for urging the driven shaft outwardlyin the axis direction.

Optimized, in the photosensitive drum the body includes a guiding holecapable of guiding the guide stem, the distance-limiting mechanismcomprises a retaining cover and a tension spring, the retaining cover isfixed to an open end of the accommodating chamber to retain part of thedriven shaft in the accommodating chamber, the tension spring isdisposed outside of the accommodating chamber with one end connected toan end of the guide stem and the other end against an end wall aroundthe guiding hole of the body.

Optimized, in the photosensitive drum the distance-limiting mechanismcomprises a retaining cover and a urging spring. The retaining cover ismounted on an open end of the accommodating chamber to retain the drivenshaft. The urging spring is interposed between the output arms and abottom wall of the accommodating chamber for urging the driven shaftoutwardly in the axis direction. A gap is provided between an end of thedriven shaft and the bottom wall when the driven shaft is at a farthestposition from the bottom wall. The gap has a axial length that is longerthan an axial length of the projection.

Optimized, in the photosensitive drum the distance-limiting mechanismcomprises a retaining cover, a first magnet and a second magnet. Theretaining cover is mounted on an open end of the accommodating chamberto retain the driven shaft. The first magnet is fixed to an end of theguide stem that is opposite to the coupling head. The second magnet isfixed on an bottom wall of the accommodating chamber with a gap awayfrom the first magnet. The first and second magnets are disposed suchthat each has a same polarity facing each other. The gap has a axiallength that is longer than an axial length of the projection.

Optimized, in the photosensitive drum the distance-limiting mechanismcomprises a retaining cover, a first magnet and a second magnet. Theretaining cover is mounted on an open end of the accommodating chamberto retain the driven shaft. The first magnet is fixed to an end of theguide stem that is opposite to the coupling head. The second magnet isfixed on an bottom wall of the accommodating chamber with a gap awayfrom the first magnet. The first and second magnets are disposed suchthat each has a same polarity facing each other. The gap has a axiallength that is longer than an axial length of the projection.

Optimized, in the photosensitive drum the distance between an outer wallof the projection in a radial direction away from the axial line of theguide stem and the extended axial line of the guide stem reducesgradually along the extending direction of the projection.

Optimized, in the photosensitive drum the projection has a rectanglarshape in a cross section parallel to the axial direction of the guidestem.

Optimized, in the photosensitive drum the projection has a step at theouter wall of the guide stem in a cross section parallel to the axialdirection of the guide stem. The distance between the step and theextended axial line of the guide stem is tapered in the extendingdirection of the projection.

Optimized, in the photosensitive drum the projection has a trapezoidalshape in a cross section parallel to the axial direction of the guidestem, and the bevel edge of the trapezoid is out of the guide stem inthe radial direction. The distance between the bevel edge and theextended axial line of the guide stem is tapered in the extendingdirection of the projection away from the guide stem.

To achieve the aforementioned objects, the present invention alsoprovides a process cartridge including a photosensitive drum. Thephotosensitive drum includes a drum cylinder and a torque receivingassembly. The body includes a guiding hole capable of guiding the guidestem. The distance-limiting mechanism comprises a retaining cover and atension spring. The retaining cover is fixed to an open end of theaccommodating chamber to retain part of the driven shaft in theaccommodating chamber. The tension spring is disposed outside of theaccommodating chamber with one end is connected to an end of the guidestem and the other end is against to an end wall around the guiding holeof the body.

Advantageously, in the process cartridge the accommodating chamber is acylindrical chamber provided coaxially with the body.

Advantageously, in the process cartridge the accommodating chamber ofthe torque receiving assembly is a regular polygon chamber providedcoaxially with the body.

Advantageously, in the process cartridge a recess recessing inwardly inthe axial direction of the guide stem is provided at central portion ofthe outer end wall of the torque receiving assembly.

Advantageously, in the process cartridge the recess of the torquereceiving assembly has a spherical shape. The center of the recess isprovided on the axial line of the guide stem.

Advantageously, in the process cartridge the outer wall of the recesshas a polygon shape in a cross section vertical to the axial directionof guide stem. The center of a phantom circle connecting all anglepoints of the polygon is provided on the extended axial line of theguide stem.

Advantageously, in the process cartridge a portion around the recess ofthe end wall of the coupling head is curved and projecting away from theguide stem in the axial direction of the guide stem.

Advantageously, in the process cartridge the body includes a guidinghole capable of guiding the guide stem along the axis direction, thedistance-limiting mechanism comprises a retaining cover and an urgingspring, the retaining cover is fixed to an open end of the accommodatingchamber to retain part of the driven shaft in the accommodating chamber,the urging spring is interposed between the output arms and a bottomwall of the accommodating chamber for urging the driven shaft outwardlyin the axis direction.

Advantageously, in the process cartridge the body includes a guidinghole capable of guiding the guide stem. The distance-limiting mechanismcomprises a retaining cover and a tension spring. The retaining cover isfixed to an open end of the accommodating chamber to retain part of thedriven shaft in the accommodating chamber. The tension spring isdisposed outside of the accommodating chamber with one end connected toan end of the guide stem and the other end against an end wall aroundthe guiding hole of the body.

Advantageously, in the process cartridge the distance-limiting mechanismcomprises a retaining cover and an urging spring. The retaining cover ismounted on an open end of the accommodating chamber to retain the drivenshaft. The urging spring is interposed between the output arms and abottom wall of the accommodating chamber for urging the driven shaftoutwardly in the axis direction. A gap is provided between an end of thedriven shaft and the bottom wall when the driven shaft is at a farthestposition from the bottom wall. The gap has a axial length that is longerthan an axial length of the projection.

Advantageously, in the process cartridge the distance-limiting mechanismof the torque receiving assembly comprises a cover, a first magnet and asecond magnet. The cover is fixed to the outer open of the accommodatingchamber. The position of the output arm is limited in the accommodatingchamber by the cover. The first magnet is fixed to the end of the guidestem opposite to the input head. The second magnet is fixed on thebottom wall of the accommodating chamber opposite the outer open. Thesurfaces of the first magnet and the second magnet which are facing eachother have the same polarity. A gap is provided between the first andsecond magnet in the axial direction of the body. The width of the gapin the axial direction of the body is longer than a projecting lengthprojected in the axial direction of the accommodating chamber of adistance between the outer end wall of the input head and the extendingend of the projection in the axial direction of the accommodatingchamber.

Advantageously, in the process cartridge the distance-limiting mechanismcomprises a retaining cover, a first magnet and a second magnet. Theretaining cover is mounted on an open end of the accommodating chamberto retain the driven shaft. The first magnet is fixed to an end of theguide stem that is opposite to the coupling head. The second magnet isfixed on an bottom wall of the accommodating chamber with a gap awayfrom the first magnet. The first and second magnets are disposed suchthat each has a same polarity facing each other. The gap has a axiallength that is longer than an axial length of the projection.

Advantageously, in the process cartridge the distance between an outerwall of the projection in a radial direction away from the axial line ofthe guide stem and the extended axial line of the guide stem is taperedin the extending direction of the projection away from the guide stem.

Advantageously, in the process cartridge the projection has arectangular shape in a cross section parallel to the axial direction ofthe guide stem.

Advantageously, in the process cartridge the projection has a step atthe outer wall of the guide stem in a cross section parallel to theaxial direction of the guide stem. The distance between the step and theextended axial line of the guide stem is tapered in the extendingdirection of the projection.

Advantageously, in the process cartridge the projection has a trapezoidshape in a cross section parallel to the axial direction of the guidestem, and the bevel edge of the trapezoid is out of the guide stem inthe radial direction. The distance between the bevel edge and theextended axial line of the guide stem is tapered in the extendingdirection of the projection.

With regard to the problem of the ball-type universal joint fortransmitting rotational force easily detachment from the drum gear, thepresent invention provides a torque receiving assembly. The torquereceiving assembly provides an input arm on its body, and the concertedrelationship between a driven shaft and the body is capable of movingreciprocally to each other in the axial or longitudinal direction of thebody. A distance-limiting mechanism defines a moving area of the drivenshaft in the axial direction of the body, and simultaneously a cover ofthe distance-limiting mechanism limits the output arm in theaccommodating chamber, so that the driven shaft as integrated is fixedto the body. In such constitution method, the input arm of the body isreceiving a rotational driving force from the output arm of the drivenshaft, and causing the body to rotate, then to drive other workingcomponents into a rotation working state. At the same time, thedistance-limiting mechanism defines the moving area of the driven shaftin the axial direction of the body, and limits the guide stem of drivenshaft in the accommodating chamber of the body, to avoid the risk of thedriven shaft dropping from the body, so that reliability and stabilitycan be maintained during rotational force transmitting of the wholetorque receiving assembly. The photosensitive drum and process cartridgeusing such torque receiving assembly have the merit of stably mounting,and reliable and stable during driving force transmitting.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 schematically illustrates the main structures of the conventionallaser printer.

FIG. 2 is a perspective view of a torque receiving assembly according toan embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of the torque receivingassembly according to the embodiment of the present invention.

FIG. 4 is an exploded perspective view of the torque receiving assemblyaccording to the embodiment of the present invention.

FIGS. 5 a and 5 b are perspective views of a body of the torquereceiving assembly according to the embodiment of the present invention.

FIG. 6 is a side view of a driven shaft of the torque receivingassembly, as seen from the drive shaft side, according to the embodimentof the present invention.

FIGS. 6 a and 6 b are cross-sectional views taken along A-A and B-B inFIG. 6 respectively.

FIGS. 7 a and 7 b are perspective views which illustrate an assemblystate of the driven shaft and a distance-limiting mechanism of thetorque receiving assembly according to the embodiment of the presentinvention.

FIG. 8 is a perspective view of a photosensitive drum according to anembodiment of the present invention.

FIG. 9 is a perspective view of a process cartridge according to anembodiment of the present invention.

FIG. 10 schematically illustrates coupling process of the torquereceiving assembly with the drive shaft according to the embodiment ofthe present invention and an external output device.

FIGS. 11 a and 11 b are cross-sectional views of a torque receivingassembly according to a second embodiment of the present invention.

FIGS. 12 a and 12 b are cross-sectional views of a torque receivingassembly according to a third embodiment of the present invention.

FIGS. 13 a and 13 b are cross-sectional views of a torque receivingassembly according to a fourth embodiment of the present invention.

FIG. 14 is partial cross-sectional view of a torque receiving assemblyaccording to a fifth embodiment of the present invention.

FIG. 15 is partial cross-sectional view of a torque receiving assemblyaccording to a sixth embodiment of the present invention.

FIG. 16 is partial cross-sectional view of a torque receiving assemblyaccording to a seventh embodiment of the present invention.

FIG. 17 is partial cross-sectional view of a torque receiving assemblyaccording to an eighth embodiment of the present invention.

FIG. 18 is partial cross-sectional view of a torque receiving assemblyaccording to a ninth embodiment of the present invention.

FIG. 19 is a perspective view which illustrates a driven shaft of atorque receiving assembly according to a tenth embodiment of the presentinvention.

FIG. 20 is a perspective view which illustrates a body of a torquereceiving assembly according to an eleventh embodiment of the presentinvention.

FIG. 21 is a perspective view of a torque receiving assembly accordingto a twelfth embodiment of the present invention.

FIG. 22 is an exploded perspective view of the torque receiving assemblyof FIG. 21.

FIG. 23 is another perspective view of the torque receiving assembly ofFIG. 21 with the retaining cover omitted.

FIG. 24 is a perspective view to show the inner structures of the bodyof the torque receiving assembly of FIG. 21.

DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

The torque receiving assembly and photosensitive drum and imagineforming process cartridge for laser printer according to the presentinvention will be described in the detailed description of particularembodiments of the invention, with reference being made to the drawings.

FIGS. 2-9 are perspective or cross-sectional views which illustrate atorque receiving assembly, a photosensitive drum and a process cartridgefor a laser printer according to a first embodiment of the presentinvention from different perspective angles and cross-sections, and FIG.10 is a schematic drawing which illustrates a coupling process of thedriven shaft of the torque receiving assembly according to theembodiment of the present invention and a drive shaft of the laserprinter. In all of FIGS. 1 to 10 of the present invention, drive shaft205 is shown in dashed line, as it is not a constituent part of thepresent invention.

The main or basic construction of a torque receiving assembly, thephotosensitive drum for the laser printer and the image forming processcartridge are generally similar to those of the prior art. A personskilled in the art could know the basic construction of a torquereceiving assembly, a photosensitive and a process cartridge in light ofprior art documents combined with the background introduction of thisinvention. Therefore, as to similar structures, those will not bedescribed in detail. A same reference symbol may be used to indicate acomponent or part having a same function as that in the prior art.Furthermore, as an object of the present invention is to solve theeasily detachment problem of the ball-type universal joint in theconventional torque transferring mechanism and provide suitablesolutions, the structure relating to prevent detachment of the torquereceiving assembly will be particularly described.

FIG. 2 illustrates an engagement state where a torque receiving assembly200 of the present invention engages with a drive shaft 205. By this, atorque, i.e., the rotational drive force, is able to be transferred fromthe drive shaft 205 to the torque receiving assembly 200, so that thetorque receiving assembly 200 is able to rotate around a rotationalaxis.

Referring to FIGS. 3-5, the torque receiving assembly 200 includes abody 201, an urging spring 202, a retaining cover 203 and a driven shaft204. The driven shaft 204 is disposed in the center of the body 201 toreceive a torque from the drive shaft 205. The torque received by thedriven shaft 204 is then transmitted to the body 201.

The body 201 has a general hollow cylindrical shape, with a helical gearportion 206 provided on its outer circumference wall for transmittingthe rotational driving force received by the body 201 to other membersof the process cartridge.

The body 201 includes an insert portion 207, which is provided with aplurality of grooves 208. The grooves 208, spaced away from each otherin a circumferential direction, are configured to provide adequatebuffer space when the body 201 is inserted into one end of drum cylinder114 (FIG. 8). The grooves 208 may be filled with glue so that theconnection between the drum cylinder 114 and the body 201 would begreatly enhanced. Since the insert portion is also called a drivingforce transferring portion, as it would transfer driving force from thebody 201 to rotate the drum cylinder 114 (FIG. 8).

Inside the body 201 is provided with an accommodating chamber 209 foraccommodating part of the driven shaft 204 and a guiding hole 212 forguiding the driven shaft along the axis direction. The accommodatingchamber 209 opens at its upper end where the retaining cover 203 ismounted, and communicates with the guiding hole 212 at its bottom end.Both the accommodating chamber 209 and the guiding hole 212 are coaxialwith the body 201. It is preferable that the guiding hole 212 is inclearance fit with the guide stem 215 of the driven shaft.

Input arms 210, are provided on cylindrical inner wall of theaccommodating chamber 209 and are rotational-symmetrically distributedaround the axial line of the body 201. The number of the input arms maybe two. The input arms 210 extend toward the enter portion of the body201, and end at a phantom circle 211. The center of the phantom circle211 is located on the axial line of the accommodating chamber 209. Thediameter of the phantom circle 211 is slightly bigger than a diameter ofa guide stem 215 which will be described hereinafter. The extendingdirections of the two input arms 210 are parallel to each other and donot intersect at the axial line of the accommodating chamber 209.

The interval between the input arms 210 along the circumferentialdirection defines an angle with which the driven shaft 204 is able torotate around the rotational axis relative to the body 201 such that thedriven shaft 204 is able to adjust its posture if necessary. In thisembodiment, the defined angle is an obtuse angle. In other words, thedriven shaft 204 is able to rotate freely about an angle which is morethan 90 degree and less than 180 degree, so that it is easier for thedriven shaft 204 to engage with or disengage from the drive shaft 205.

Position posts 213 extending toward the axial line of the body 201 areradial symmetrically provided on the inner cylindrical wall of theaccommodating chamber 209. The radial length of the position posts 213is less than that of the input arms 210.

Each of the position posts 213 and input arms 210 is provided with astep portion 214 at an end opposite to the insert portion 207, whichprovides a mounting seat for the retaining cover 203 when the retainingcover 203 is fixed to the body 201.

The driven shaft 204 includes a cylindrical guide stem 215 and acoupling head 216 provided at one axial end of the guide stem 215. Thecoupling head 216 has a general plate shape, with two projections 220extending outwardly in the axial direction thereof. The maximumtransverse dimension of the coupling head is bigger than that of theguide stem 215. Cylindrical output arms 217 are provided on the outerperipheral wall of the guide stem 215 and extends outward in a radialdirection. There may be two output arms symmetrically distributedradially around the axial line of the guide stem 215. The output arms217 are configured to contact with the input arms 210 to transfer atorque.

A spherical recess 219 is provided on outer end wall 218 of the couplinghead 216 at the center portion. The spherical center of the recess 219is located on the rotational line or axial line of the guide stem 215.Projections 220 are provided on the outer end wall 218 around the recess219 and extend from the outer end wall 218 to a pre-determined length inthe axial direction of the guide stem 215. The length is longer than adiameter of a drive pin 230 which will be described hereinafter.Referring to FIG. 6, FIGS. 6 a and 6 b, the dimension of the projectionsin the radial direction of the guide stem 215 is tapered along theextending direction. Or in more detail, at the driven side of theprojection 220, which is a side opposite to the guide stem 215, thedistance between the outmost portion of the projection 220 in the radialdirection of the guide stem 215 and the axial line of the guide stemreduces gradually along the extending direction of the projection, thusforming a smooth blending surface 221. The projections may be two, andare symmetrically distributed around the axial line of the guide stem215.

As an improvement, an adjustment may be made on the portion around therecess 219 of the outer end wall 218 in the coupling head 216, that is,the portion of the outer end wall 218 around the recess 219 can protrudeoutward away from the guide stem 215 along the axial direction of theguide stem 215. Thus, a ridged-convex surface 222 can be formed.Specifically, the portion of the outer end wall 218 around the recess219 forms a ridged-convex surface 222 while protruding away from theguide stem 215 along the axial direction of the guide stem 215, so thatthe ridged-convex surface 222 has an outer portion and an inter portionin the radial direction of the guide stem at a cross-section parallel tothe axial direction of the guide stem 215. Related to the outer portionof the ridged-convex surface 222 in the radial direction of the guidestem 215, the distance between the ridged-convex surface 222 and theaxial line of the guide stem 215 decreases as the distance from theguide stem 215 increases, thus forming a blending surface 223. Relatedto the inner portion of the ridged-convex surface 222 in the radialdirection of the guide stem 215, the distance between the ridged-convexsurface 222 and the axial line of the guide stem 215 is expanding in theextending direction away from the guide stem, thus forming a bendingsurface 224. In a cross-section parallel to the axial direction of theguide stem 215, the blending surfaces 223 and 224 connect smoothly atthe end portion of the outer end wall 218 in the axial direction of theguide stem 215, and the connecting portions are protruding away from theguide stem 215, and forming the ridged-convex surface 222. In across-section parallel to the axial direction of the guide stem 215, theend of the blending surface 224 connects the recess 219 smoothly in theradial direction of the guide stem.

The retaining cover 203 is mainly like a disc. Eight notches 225 areprovided on the outer peripheral portion of the cover and symmetricaldistributed about the central line of the retaining cover 203.

The notches 225 are provided with configurations corresponding to thestep portions 214 in such a way that the retaining cover 203 is able tobe mounted on the body 201 at a proper position. A round hole 226 isprovided at the central portion of the retaining cover 203. The hole 226is in clearance fit with or slightly bigger than the guide stem 215, sothat the guide stem 215 can move in the rotational axis directionrelative to the cover 203. A slot 227 is provided co-axially with thehole 226, with one overlapped with the other. The size of the slot 227is bigger than the diameter of the arms 217, so the output arms 217 canpass through the slot 227 when mounting the driven shaft 204 onto thebody 201.

As a component of a laser beam printer, the drive shaft 205 has acylindrical body 228. At an end of the cylindrical body 228 in the axialdirection, a spherical head 229 is provided. The other end of thecylindrical body 228 in the axial direction couples with a rotationaldriving force output mechanism (not shown) such as a driving shaft ofthe laser printer. A drive pin 230, which is perpendicular to therotational axis of the drive shaft 205, are provided adjacent to thehead 229. The spherical center of the head 229 is positioned on therotational axis of the drive shaft 205.

In the process of assembling the torque receiving assembly 200, theguide stem 215 with the arms 217 will penetrate the central hole 226with the slot 227 until the guide stem 215 enters the guiding hole 212.After the cover 203 is fixed to body 201, the arms 217 are offset fromthe slot 227 (referring to FIGS. 7 a and 7 b), such that the drivenshaft 204 is retained in the body 201. By this, the driven shaft 204 isprevented from disengaging from the body 201.

Once assembled, the torque receiving assembly 200 has the followingrelations among the elements. A segment of the guide stem 215 from thefree end to the output arm 217 is limited in the accommodating chamber209. The coil spring 202 is set around a segment of the guide stem 215between the bottom surface of the accommodating chamber 209 and theoutput arms 217. One end of the urging spring 202 is against a portionof the output arms 217 which is facing the bottom surface of theaccommodating chamber 209, the other end is against the bottom wall 231of the accommodating chamber 209. In the circumferential direction ofthe accommodating chamber 209, the output arms 217 are ready forengagement with the input arms 210. The free end of the guide stem 215is inserted into the guiding hole 212, the guide stem 215 can movereciprocally in the axial direction of the guiding hole 212 relative tothe guiding hole 212 and the accommodating chamber 209. In the axialreciprocating movement of the guide stem 215, a distance-limitingmechanism 232, including the retaining cover 203 and the urging spring202, defines a maximum distance the driven shaft 204 is able to moverelative to the body 201 in the axial direction. The maximum distanceequals a distance of the output arm 217 from the cover 202 to a positionwhere the compression dead point of the coil spring 202 is achieved. Inother words, in the axis direction, the driven shaft 204 is movablerelative to the body 201 between a first position where the output arms217 of the driven shaft 204 makes contact with the retaining cover 203and a second position where the urging spring 202 interposed between theoutput arms 217 and the bottom wall 231 of the chamber 209 arecompletely compressed into a dead point by the output arms 217.

With the drive shaft 205 engaging the driven shaft 204, the sphericalhead 229 and the outer end wall 218 of the coupling head 216 face eachother and the state is maintained, wherein the spherical head 229 ispressed into the recess 219 of the driven shaft 204, the drive pin 230contacts with and against the projections 220 in the circumferentialdirection of guide stem 215, and the center of the spherical head 229 ispositioned at the axis. Specifically, when the driven shaft 204 ispressed by the drive shaft 205, the urging spring 202 will retreattoward the insert portion 207 along the guiding hole 212 by elasticity,until a space needed for engagement of the drive shaft 205 and thecoupling head 216 is released. The length of the space is equal to aretract distance with which the coupling head 216 is moved toward theinsert portion 207. The retract distance is longer than the axial lengthof the projection which begins at the outer end wall 218 of the couplinghead 216 and terminates at the free end of the projection 220. When thedriven shaft 204 is at a natural state, under which there is no contactbetween the drive shaft 205 and the driven shaft 204, the spring 202will push the driven shaft 204 outwardly until the output arms 217contact the retaining cover 203 in the accommodating chamber 209.

In the abovementioned construction state, when the torque receivingassembly 200 is fixed to an external torque receiving device such asdrum cylinder 114, that is, the insert portion 207 of the body 201 isinserted into the cavity of the drum cylinder 114 and fixed, aphotosensitive drum 101 having an image forming function is formed. Whenthe photosensitive drum 101 is assembled into a process cartridge havinga developing agent, and coupling with an external rotation drivingoutput device such as a drive shaft 205 of a laser printer, the processcartridge will be fully mounted into the laser printer. Referring toFIGS. 8, 9 and 10, and combining with other figures, the spherical head229 provided on the end of the drive shaft 205 of the laser printer willpress the ridged-convex surface 222 of the driven shaft 204 or theprojections 220 of the coupling head 216, and make the driven shaft 204retreat along the guiding hole 212 toward the insert portion 207, i.e.arrow x shown in FIG. 10. Simultaneously, the driven shaft 204 will movein the radial or lateral direction of the drive shaft 205, i.e. arrow yshown in FIG. 10, so the spherical head 229 of the drive shaft 205 willslide along the blending surface 223 of the ridged-convex surface 222 orthe blending surfaces 221 of the projections 220, and the sphericalrecess 219 of the coupling head 216 will gradually align with thespherical head 229 of the drive shaft 205. After perfect alignmentbetween the spherical recess 219 and the spherical head 229 is achieved,the pressure from the spherical head 229 to the driven shaft 204 isvanished, and the driven shaft 204 urged by the urging spring 202 in theopposite direction moves reversely in a z direction which is opposite tothe arrow x shown in FIG. 10, until the spherical head 229 slidesgradually and fully inserts into the spherical recess 219, whereby theengagement of the torque receiving assembly 200 and the external torqueoutput device, i.e. the laser printer, is completed. At that time, theprojections 220 of the coupling head 216 and the drive pin 230 of thedrive shaft 205 are engaged with each other. The engagement may happenafter an idle angle as the projections may not go to the contactposition at first, in other words, the projections 220 may be offsetfrom the drive pin 230 in the circumferential direction at thebeginning.

Torque generated in the laser printer is transmitted to the projections220 of the driven shaft 204 by the drive pin 230 of the drive shaft 205,then along a transmission path including the guide stem 215, the outputarm 217, the input arms 210 and the insert portion 207 to downstreamdevice, such as the drum cylinder 114 or other mechanism which isengaging with the helical gear 206, such as a developing roller 105 oran agitator (not shown).

FIGS. 11 a and 11 b are two cross-sectional views of a driven shaft of asecond embodiment of the torque receiving assembly according to theinvention. In the second embodiment, the main structure of the torquereceiving assembly is substantially the same with that of the firstembodiment. The point this second embodiment differs from the firstembodiment is that the projections 220-1 have a rectangle shape in across-section parallel to the axial direction of the guide stem 215. Theprojections 220-1 are provided on the coupling head 216 opposite to theguide stem 215 and out of the guide stem 215 in the radial direction,and extend in the axial direction away from the guide stem 215, and theopposite surfaces of the projections 220-1 are parallel to each otheralong the axial direction of the guide stem 215. In this configuration,when the spherical-shaped raised head 229 of the drive shaft 205contacts and presses the edges of the projections 220-1 or the couplinghead 216, the rectangle-shaped projections 220-1 or the blending surface223 of the coupling head 216 still will slide along the sphericalsurface of the raised head 229 for the spherical-shaped raised head 216having spherical property, and the spherical-shaped recess 219 of thecoupling head 216 will align with the spherical-shaped raised head 229gradually. After perfect alignment is achieved, the pressure from thespherical-shaped raised head 229 to the driven shaft 204 is vanished,then the driven shaft 204 is urged by the coil spring 202 in theopposite direction and moves reversely in the z direction which isopposite to arrow x shown in FIG. 10, until the spherical-shaped raisedhead 229 slides gradually and fully inserts into the spherical-shapedrecess 219, wherein the engagement of the torque receiving assembly 200and the external torque output device, i.e. the laser printer, iscompleted.

FIGS. 12 a and 12 b are two cross-sectional views of a driven shaft of athird embodiment of the torque receiving assembly according to theinvention. In the third embodiment, the main structure of the torquereceiving assembly is substantially the same with that of the firstembodiment, but differs from the first embodiment in that theprojections 220-2 have steps 234 in the cross-section parallel to theaxial direction of the guide stem 215. The distance between the steps234 and the extended axial line of the guide stem 215 becomes taperedgradually along the extending direction of the projections 220-2 awayfrom the guide stem 215. In this configuration, when thespherical-shaped raised head 229 of the drive shaft 205 contacts andpresses the edges of the projection 220-2 or the coupling head 216, asthe spherical-shaped raised head 229 having spherical property, thesteps 234 of the projections 220-1 or the blending surface 223 of thecoupling head 216 still will slide along the spherical surface of theraised head 229, and make the spherical-shaped recess 219 of thecoupling head 216 gradually align with the spherical shaped raised head229. After alignment is completed, the pressure from thespherical-shaped raised head 229 to the driven shaft 204 is vanished,then the driven shaft 204 urged by the coil spring 202 in the oppositedirection moves reversely in the z direction which is opposite to thearrow x shown in FIG. 10, until the spherical-shaped raised head 229slides gradually and fully inserts into the spherical-shaped recess 219,wherein the engagement of the torque receiving assembly 200 and theexternal torque output device, i.e. the laser printer, is completed.

FIGS. 13 a and 13 b are two cross-sectional views of a driven shaft of afourth embodiment of the torque receiving assembly according to theinvention. In the fourth embodiment, the main structure of the torquereceiving assembly is substantially the same with that of the firstembodiment, the point this embodiment differs from the first embodimentis that the projection 220-1 has a trapezoidal shape in a cross-sectionparallel to the axial direction of the guide stem 215, and a bevel edge235 of the trapezoid is out of the guide stem 215 in the radialdirection. The distance between the bevel edge 235 and the extendedaxial line of the guide stem 215 becomes tapered gradually along theextending direction of the projections 220-3 away from the guide stem215. In this configuration, when the spherical-shaped raised head 229 ofthe drive shaft 205 contacts and presses the edges of the projections220-1 or the coupling head 216, for the spherical-shaped raised headhaving spherical property, the bevel edges 235 of the projections 220-3or the blending surface 223 of the coupling head 216 still will slidealong the spherical surface of the raised head 229, and make thespherical-shaped recess 219 of the coupling head 216 gradually alignwith the spherical-shaped raised head 229. After alignment is achieved,the pressure from the spherical-shaped raised head 229 to the drivenshaft 204 is vanished, then the driven shaft 204 urged by the coilspring 202 in the opposite direction will move reversely in the zdirection which is opposite to the arrow x shown in FIG. 10, and thespherical-shaped raised head 229 will slide gradually and fully insertinto the spherical-shaped recess 219, wherein the engagement of thetorque receiving assembly and the external torque output device, i.e.the laser printer, will be completed.

FIG. 14 is a partial cross-sectional view of a fifth embodiment of thetorque receiving assembly according to the invention. In the fifthembodiment, the main structure of the torque receiving assembly issubstantially the same as that of the first embodiment. The differencewith the first embodiment is that a tension spring 202-1 is disposedoutside of the accommodating chamber 209. The specific configuration isthat the guide stem 215 is penetrating into the accommodating chamber209 and guiding hole 212 successively, and extending out of the guidinghole 212, the spring 202-1 is set around the segment of the guide stem215 which is extending out of the guiding hole. One end of the spring202-1 is fixed to the end of the guide stem 215 opposition to thecoupling head 216, the other end is connected to the end wall 240 of theguiding hole 212. Thus, the outer open of the guiding hole is in theaxial direction. In this configuration, for the spring 202-1 havingelasticity, when the drive shaft 205 urges the driven shaft 204 in theaxial direction of the guiding hole 212, the driven shaft 204 willretreat along the guiding hole 212 toward the output position 207, i.e.opposite to coupling head 216, until a space needed for engagement ofthe drive shaft 205 and the coupling head 216, i.e. a space needed forthe spherical-shaped raised head 229 sliding into the spherical recess219 is released. The length of the space is equal to a retract distancewhich the coupling head 216 is moving toward the insert portion 207. Theretract distance is longer than the height of the projections 220. Whenthe driven shaft 204 is at a natural state without pressure, the spring202-1 will draw the output arm 217 back and position it against to theouter wall of the retaining cover 203 in the accommodating chamber 209.

FIG. 15 is a partial cross-sectional view of a sixth embodiment of thetorque receiving assembly according to the invention. In the sixthembodiment, the main structure of the torque receiving assembly issubstantially the same with that of the first embodiment. The differenceis that there is no guiding hole provided on the body. The configurationis that the guide stem 215 is penetrating into the accommodating chamber209, and a gap 236 is pre-provided between the end of guide stem 215opposite to the coupling head 216 and the bottom wall 231 of theaccommodating chamber 209 in the axial direction of the accommodatingchamber 209. The bottom wall 231 and the outer open end is provided attwo ends of the accommodating chamber 209, respectively. The width ofthe gap 236 in the axial direction of the accommodating chamber 209 islonger than the length of the projection 220. The coil spring 202 is setaround a segment of the guide stem 215 which is accommodated in theaccommodating chamber 209. One end of the coil spring 202 is against theoutput arm 217, and the other end is against the bottom wall 231 of theaccommodating chamber 209. In this configuration, as the coil spring 202having elasticity, when the drive shaft 205 urges the driven shaft 204in the axial direction of the accommodating chamber 209, the drivenshaft 204 will retreat toward the output position 207, until a spaceneeded for engagement of the drive shaft 205 and the coupling head 216,i.e. a space needed for the spherical head 229 sliding into thespherical recess 219, is released. The length of the space is equal to adistance which the coupling head 216 is moving toward the insert portion207 and provided by the gap 236. The two distances are both longer thanthe length of the projection 220. When the driven shaft 204 is at anatural state, the coil spring 202 will push the output arm 217 andposition it against the retaining cover 203 in the accommodating chamber209.

FIG. 16 is a partial cross-sectional view of a seventh embodiment of thetorque receiving assembly according to the invention. In the seventhembodiment, the main structure of the torque receiving assembly issubstantially the same with that of the first embodiment, except thattwo permanent magnets replace the urging spring 202, and there is noguiding hole provided on the body 201. In this embodiment a first magnet237 is fixed to the end of the guide stem 215 opposite to the inputhead. A second magnet 238 is fixed on the bottom wall 231 of theaccommodating chamber 209 which is opposite to the outer open of theaccommodating chamber 209 in the axial direction of the body.Specifically, the bottom wall 231 and the outer open are provided at twoends of the accommodating chamber 209, respectively. In the radialdirection of the body 201, the position of the first magnet and thesecond magnet are aligned with each other. The first magnet and thesecond magnet are disposed with the same polarities facing each other.In the axial direction of body 201, a gap 239 is pre-provided betweenthe first and second magnets. The width of the gap 239 in the axialdirection of the accommodating chamber 209 is longer than a projectinglength projected in the axial direction of the accommodating chamber 209of a distance between the outer end wall 218 of the coupling head 216and the extending end of the projection 220 in the axial direction ofthe accommodating chamber 229. In this configuration, for repulsionforce generating between the first and second magnets, when the driveshaft 205 urges the driven shaft 204 in the axial direction of theaccommodating chamber 209, the driven shaft 204 will retreat toward theoutput position 207, until a space needed for engagement of the driveshaft 205 and the coupling head 216, i.e. a space needed for thespherical shaped-raised head 229 sliding into the spherical shapedrecess 219 is released. The length of the space is equal to a distancewhich the coupling head 216 is moving toward the insert portion 207 andprovided by the gap 239. The two distances are both longer than thelength of the projection 220. When the driven shaft 204 is at a naturalstate a repulsion force generating between the first and second magnetswill urge the output arm 217 and position it against the outer wall ofthe retaining cover 203 in the accommodating chamber 209, and thespherical raised head 229 will be fully inserted into the sphericalrecess 219.

FIG. 17 is a partial cross-sectional view of an eighth embodiment of thetorque receiving assembly according to the invention. In the eighthembodiment, the main structure of the torque receiving assembly issubstantially the same with that of the first embodiment, except thattwo permanent magnets replace the coiling spring 202, and there is noguiding hole provided on the body 201. The specific configuration isthat a first magnet 241 is fixed to the end of the guide stem 215opposite to the input head. A second magnet 242 is a ring fixed on theinput arm 210 in the accommodating chamber 209, the second magnet isprovided between the first magnet 241 and the output arm 217 in theaxial direction of the accommodating chamber 209. The ends of the firstmagnet and the second magnet which are facing each other have differentpolarities. The guide stem 215 is slideably penetrating into the innerwall of the second magnet. In the axial direction of the accommodatingchamber 209, a gap 243 is pre-provided between the first magnet 241 andthe bottom wall 231 of the accommodating chamber 209 which is oppositeto the outer open of the accommodating chamber 209 in the axialdirection of the body 201. Specifically, the bottom wall 231 and theouter open are provide at two ends of the accommodating chamber 209,respectively. The width of the gap 243 in the axial direction of theaccommodating chamber 209 is longer than a projecting length projectedin the axial direction of the accommodating chamber 209 of a distancebetween the outer end wall 218 of the coupling head 216 and theextending end of the projection 220 in the axial direction of theaccommodating chamber 229. In this configuration, for attraction forcegenerating between the first and second magnets, when the drive shaft205 urges the driven shaft 204 in the axial direction of theaccommodating chamber 209, the driven shaft 204 will retreat toward theoutput position 207, until a space needed for engagement of the driveshaft 205 and the coupling head 216, i.e. a space needed for thespherical shaped raised head 229 sliding into the spherical shapedrecess 219, is released. The length of the space is equal to a distancewhich the coupling head 216 is moving toward the insert portion 207provided by the gap 239. The two distances are both longer than thelength of the projection 220. When the driven shaft 204 is at a naturalstate, attraction force generating between the first and second magnetswill draw the output arm 217 back and position it against the outer wallof the retaining cover 203 in the accommodating chamber 209, and thespherical raised head 229 will be fully inserted into the sphericalrecess 219.

FIG. 18 is a partial cross-sectional view of a ninth embodiment of thetorque receiving assembly according to the invention. In the ninthembodiment, the main structure of the torque receiving assembly issubstantially the same with that of the first embodiment, but differsfrom the first embodiment in that two permanent magnets replace thecoiling spring 202, and there is no guiding hole provided on the body201. The specific configuration is that, a first magnet 244 is fixed tothe end of the guide stem 215 opposite to the input head. A secondmagnet 245 is a ring and fixed on the retaining cover 203. The ends ofthe first magnet and the second magnet which are facing each other havedifferent polarity. The guide stem 215 is slideably penetrated into thesecond magnet 245. In the axial direction of the accommodating chamber209, a gap 246 is pre-provided between the first magnet 244 and thebottom wall 231 of the accommodating chamber 209 opposite to the outeropen of the accommodating chamber 209 in the axial direction of thebody. Specifically, the bottom wall 231 and the outer open are provideat two ends of the accommodating chamber 209, respectively. The width ofthe gap 246 in the axial direction of the accommodating chamber 209 islonger than the length of the projection 220. The output arm 217 and theguide stem 215 mate with each other in a movable manner, that is, achannel is provided on the guide stem 215 for accommodating the outputarm 217, after the guide stem 215 penetrates into the retaining cover203 and the output arm 217 is fixed in the channel. In thisconfiguration, for attraction force generating between the first andsecond magnets, when the drive shaft 205 urges the driven shaft 204 inthe axial direction of the accommodating chamber 209, the driven shaft204 will retreat toward the output position 207 until a space needed forengagement of the drive shaft 205 and the coupling head 216, i.e. aspace needed for the spherical shaped raised head 229 sliding into thespherical shaped recess 219, is released. The length of the space isequal to a distance which the coupling head 216 is moving toward theinsert portion 207 provided by the gap 239. The two distances are bothlonger than the length of the projection 220. When the driven shaft 204is at a natural state without pressure, attraction force generatingbetween the first and second magnets will draw the output arm 217 backagainst the outer wall of the retaining cover 203 in the accommodatingchamber 209, and the spherical head 229 will be fully inserted into thespherical recess 219.

FIG. 19 is a perspective view of a driven shaft 204 of a tenthembodiment of the torque receiving assembly according to the invention.In the tenth embodiment, the main structure of the torque receivingassembly is substantially the same with that of the first embodimentthis embodiment differs from the first embodiment in that the shape ofthe recess of the coupling head 216 provided on the outer end wall 218and recessing in the longitude direction of the guide stem 215 is aregular octagon, not spherical. The specific configuration is that therecess 219-1 provided on the outer wall 247 of the guide stem 215(referring to the figures for the first embodiment) in a cross-sectionperpendicular to the axial direction of the guide stem 215 has a regularoctagon shape. A center of a circle which passes all the angle points islocated at the extended axial line of the guide stem 215. Certainly, theshape of the recess 219-1 in a cross-section perpendicular to the axialdirection of the guide stem 215 can be other regular polygons such astriangle, square or pentagon, etc.

FIG. 20 is a perspective view of a body 201 of an eleventh embodiment ofthe torque receiving assembly according to the invention. In theeleventh embodiment, the main structure of the torque receiving assemblyis substantially the same with that of the first embodiment. Thisembodiment differs from the first embodiment in that the shape of theaccommodating chamber 208 of the body 210 is a square 209-1, and thereis no guide stem 213 and step 214 provided on the inner wall of thesquare chamber 209-1. The specific configuration is that, in across-section perpendicular to the axial direction of the body 201, thetwo diagonals of the square meet each other at the center line of thesquare chamber, and the center line is extending in the axial directionof the body and coinciding with the axial line of the body 201. Theinput arms 210 in the square chamber 209-1 extending only to a positionwhich is flush with the edges 248 of the outer open of the squarechamber 209-1 in the axial direction of the body 201, so that a step isformed between the outer wall 249 of the input arm 210 in the axialdirection of the body 201 and the edges of the outer open of the squarechamber 209-1, a retaining cover 203 with shape adjusted forcorresponding to the square chamber 209-1 (referring to the figures forthe first embodiment) is fixed on the outer open of the square chamber209-1. Certainly, the projection shape of the recess 219-1 can be otherregular polygons such as triangle, square or pentagon, etc.

Referring to FIGS. 21-24, the 12th embodiment of the present inventionwill now be described.

The point in which the present embodiment differs from the firstembodiment illustrated in FIGS. 2-6 is in the way the driven shaft isinitially positioned relative to the body in the rotational directionand the structure with respect to it.

In the torque receiving assembly 200, the urging spring 202 is a coilspring having an upper tail 202 a adjacent to the output arms 217 and abottom tail 202 b adjacent to the bottom of the chamber 209 of the body201 along the longitudinal direction. The urging spring 202 is disposedaround the driven shaft 204 with the upper tail 202 a hooked by theoutput arm 217 and the bottom tail 202 b restricted in the recess 249which is formed between the input arms 210 and the restricting rib 250,such that the driven shaft 204 are initially disposed at a predeterminedcircumferential position where the output arms 217 is kept at a distanceaway from the input arms 210 along the circumferential direction. Duringmounting of a process cartridge having this torque receiving assembly200, the driven shaft 204 with its coupling head is able to adjust itsposture in a clockwise direction or counter-clockwise direction when thecoupling head is confronting the drive shaft of the printer. Therefore,mounting operativity in mounting a process cartridge having this torquereceiving assembly in a printer is improved.

If the output arms 217 are not kept away from the input arms 210, duringmounting operation, when the coupling head confronts with the driveshaft in a condition that one of projections 220 abuts drive pin 230, itwould sometimes cause a “dead point” where it is very hard for thedriven shaft to move forward along the mounting direction to finish theengagement between the projections and the drive pin. Therefore, theabove mentioned predetermined circumferential position of the drivenshaft will avoid that “dead point”, as there is room for the drivenshaft to adjust its postures before the coupling engagement.

In addition, in this embodiment, output arms 217 are provided by a pinindependently formed and slidably connected to the driven shaft 204through a through-hole. As such, the drive shaft is able to be made bymetal in a simple way.

Thus, while there have shown and described and pointed out fundamentalnovel features of the invention as applied to a preferred embodimentthereof, it will be understood that various omissions and substitutionsand changes in the form and details of the devices illustrated, and intheir operation, may be made by those skilled in the art withoutdeparting from the spirit of the invention. For example, it is expresslyintended that all combinations of those elements and/or method stepswhich perform substantially the same function in substantially the sameway to achieve the same results are within the scope of the invention.Moreover, it should be recognized that structures and/or elements and/ormethod steps shown and/or described in connection with any disclosedform or embodiment of the invention may be incorporated in any otherdisclosed or described or suggested form or embodiment as a generalmatter of design choice. It is the intention, therefore, to be limitedonly as indicated by the scope of the claims appended hereto.

1. A torque receiving assembly, comprising: a body having an axis and having an accommodating chamber; a driven shaft disposed coaxially with said body, the driven shaft including a guide stem and a coupling head provided at one axial end of said guide stem, the guide stem having at least one output arm which extends outwardly in a radial direction, the coupling head having a plurality of projections; wherein at least one input arm is provided at an inner wall of the accommodating chamber and configured for abutting the at least one output arm; the guide stem is movable in the axial direction relative to the body, and the torque receiving assembly further comprises a distance-limiting mechanism that defines a maximum distance the driven shaft is able to move relative to the body in the axis direction.
 2. The torque receiving assembly according to claim 1, wherein the coupling head has a recess that is coaxial with the driven shaft and has a rotationally symmetric shape; the at least one input arm comprises a pair of input arms, the at least one output arm comprises a pair of output arms, and the interval between the input arms along a circumferential direction defines an obtuse angle with which the driven shaft is able to rotate freely relative to the body around the axis.
 3. The torque receiving assembly according to claim 2, wherein a portion of the coupling head around the recess is curved and projecting away from the guide stem in the axis direction.
 4. The torque receiving assembly according to claim 1, wherein the body comprises a guiding hole capable of guiding the guide stem along the axis direction, the distance-limiting mechanism comprises a retaining cover and an urging spring, the retaining cover is fixed to an open end of the accommodating chamber to retain part of the driven shaft in the accommodating chamber, the urging spring is interposed between the output arms and a bottom wall of the accommodating chamber for urging the driven shaft outwardly in the axis direction.
 5. The torque receiving assembly according to claim 3, wherein the body comprises a guiding hole capable of guiding the guide stem along the axis direction, the distance-limiting mechanism comprises a retaining cover and an urging spring, the retaining cover is fixed to an open end of the accommodating chamber to retain part of the driven shaft in the accommodating chamber, the urging spring is interposed between the output arms and a bottom wall of the accommodating chamber for urging the driven shaft outwardly in the axis direction.
 6. The torque receiving assembly according to claim 1, wherein the body comprises a guiding hole capable of guiding the guide stem, the distance-limiting mechanism comprises a retaining cover and a tension spring, the retaining cover is fixed to an open end of the accommodating chamber to retain part of the driven shaft in the accommodating chamber, the tension spring is disposed outside of the accommodating chamber with one end connected to an end of the guide stem and the other end against an end wall around the guiding hole of the body.
 7. The torque receiving assembly according to claim 3, wherein the body comprises a guiding hole capable of guiding the guide stem, the distance-limiting mechanism comprises a retaining cover and a tension spring, the retaining cover is fixed to an open end of the accommodating chamber to retain part of the driven shaft in the accommodating chamber, the tension spring is disposed outside of the accommodating chamber with one end connected to an end of the guide stem and the other end against an end wall around the guiding hole of the end body.
 8. The torque receiving assembly according to claim 1, wherein the distance-limiting mechanism comprises a retaining cover and an urging spring, the retaining cover is mounted on an open end of the accommodating chamber to retain the driven shaft, the urging spring is interposed between the output arms and a bottom wall of the accommodating chamber for urging the driven shaft outwardly in the axis direction, a gap is provided between an end of the driven shaft and the bottom wall when the driven shaft is at a farthest position from the bottom wall, the gap has a axial length that is longer than an axial length of the projection.
 9. The torque receiving assembly according to claim 3, wherein the distance-limiting mechanism comprises a retaining cover and a urging spring, the retaining cover is mounted on an open end of the accommodating chamber to retain the driven shaft, the urging spring is interposed between the output arms and a bottom wall of the accommodating chamber for urging the driven shaft outwardly in the axis direction, a gap is provided between an end of the driven shaft and the bottom wall when the driven shaft is at a farthest position from the bottom wall, the gap has a axial length that is bigger than an axial length of the projection.
 10. The torque receiving assembly according to claim 1, wherein the distance-limiting mechanism comprises a retaining cover, a first magnet and a second magnet, the retaining cover is mounted on an open end of the accommodating chamber to retain the driven shaft, the first magnet is fixed to an end of the guide stem that is opposite to the coupling head, the second magnet is fixed on an bottom wall of the accommodating chamber with a gap away from the first magnet, the first and second magnets are disposed such that each has a same polarity facing each other, the gap has an axial length that is longer than an axial length of the projection.
 11. The torque receiving assembly according to claim 3, wherein the distance-limiting mechanism comprises a retaining cover, a first magnet and a second magnet, the retaining cover is mounted on an open end of the accommodating chamber to retain the driven shaft, the first magnet is fixed to an end of the guide stem that is opposite to the coupling head, the second magnet is fixed on a bottom wall of the accommodating chamber with a predetermined gap away from the first magnet, the first and second magnets are disposed such that each has a same polarity facing each other.
 12. The torque receiving assembly according to claim 1, wherein the distance-limiting mechanism comprises a retaining cover, a first magnet and a second magnet, the retaining cover is mounted on an open end of the accommodating chamber to retain the driven shaft, the first magnet is fixed to an end of the guide stem that is opposite to the coupling head, the at least one output arm comprises a pair of output arms, the second magnet is formed as a ring and is disposed in the accommodating chamber at a position that is between the output arms and the first magnet with respect to the axis direction, the first and second magnets are disposed such that each has a different polarity facing each other.
 13. The torque receiving assembly according to claim 3, wherein the distance-limiting mechanism comprises a retaining cover, a first magnet and a second magnet, the retaining cover is mounted on an open end of the accommodating chamber to retain the driven shaft, the first magnet is fixed to an end of the guide stem that is opposite to the coupling head, the second magnet is formed as a ring and is disposed in the accommodating chamber at a position that is between the output arms and the first magnet with respect to the axis direction, the first and second magnets are disposed such that each has a different polarity facing each other.
 14. The process cartridge according to claim 2, wherein the driven shaft includes a through-hole substantially perpendicular to the axis direction, wherein a pin is slideably received in the through-hole, and wherein ends of the pin comprise the pair of output arms.
 15. The process cartridge according to claim 14, wherein the pin is comprised of metal.
 16. A photosensitive drum, including a drum cylinder and a torque receiving assembly, the torque receiving comprising: a body having an axis and having an accommodating chamber; a driven shaft disposed coaxially with said body, the driven shaft including a guide stem and a coupling head provided at one axial end of said guide stem, the guide stem having a pair of output arms which extend outwardly in a radial direction, the coupling head having a plurality of projections; wherein a pair of input arms are provided at an inner wall of the accommodating chamber and configured for abutting with the output arms; the guide stem is movable in the axial direction relative to the body, and the torque receiving assembly further comprises a distance-limiting mechanism that defines a maximum distance the driven shaft is able to move relative to the body in the axis direction.
 17. The photosensitive drum according to claim 16, wherein the body comprises a guiding hole capable of guiding the guide stem along the axis direction, the distance-limiting mechanism comprises a retaining cover and a urging spring, the retaining cover is fixed to an open end of the accommodating chamber to retain part of the driven shaft in the accommodating chamber, the urging spring is interposed between the output arms and a bottom wall of the accommodating chamber for urging the driven shaft outwardly in the axis direction.
 18. The photosensitive drum according to claim 16, wherein the body comprises a guiding hole capable of guiding the guide stem, the distance-limiting mechanism comprises a retaining cover and a tension spring, the retaining cover is fixed to an open end of the accommodating chamber to retain part of the driven shaft in the accommodating chamber, the tension spring is disposed outside of the accommodating chamber with one end connected to an end of the guide stem and the other end against an end wall around the guiding hole of the body.
 19. A process cartridge, including a photosensitive drum, and the photosensitive drum including a drum cylinder and a torque receiving assembly, the torque receiving assembly having a body including a guiding hole capable of guiding a guide stem, a distance-limiting mechanism comprising a retaining cover and a tension spring, the retaining cover is fixed to an open end of an accommodating chamber to retain part of a driven shaft in the accommodating chamber, the tension spring is disposed outside of the accommodating chamber with one end connected to an end of the guide stem and the other end against an end wall around the guiding hole of the body.
 20. The process cartridge according to claim 19, wherein the body comprises a guiding hole capable of guiding the guide stem along the axis direction, the distance-limiting mechanism comprises a retaining cover and an urging spring, the retaining cover is fixed to an open end of the accommodating chamber to retain part of the driven shaft in the accommodating chamber, the urging spring is interposed between output arms and a bottom wall of the accommodating chamber for urging the driven shaft outwardly in the axis direction.
 21. The process cartridge according to claim 19, wherein the body comprises a guiding hole capable of guiding the guide stem, the distance-limiting mechanism comprises a retaining cover and a tension spring, the retaining cover is fixed to an open end of the accommodating chamber to retain part of the driven shaft in the accommodating chamber, the tension spring is disposed outside of the accommodating chamber with one end connected to an end of the guide stem and the other end against an end wall around the guiding hole of the body.
 22. The process cartridge according to claim 19, wherein the distance-limiting mechanism comprises a retaining cover and an urging spring, the retaining cover is mounted on an open end of the accommodating chamber to retain the driven shaft, the urging spring is interposed between the output arms and a bottom wall of the accommodating chamber for urging the driven shaft outwardly in the axis direction, a gap is provided between an end of the driven shaft and the bottom wall when the driven shaft is at a farthest position from the bottom wall, the gap has a axial length that is longer than an axial length of the projection.
 23. The process cartridge according to claim 20, wherein the guide stem includes a through-hole substantially perpendicular to the axis direction, wherein a pin is slidably received in the through-hole, and wherein ends of the pin comprise the output arms.
 24. The process cartridge according to claim 23, wherein the pin is comprised of metal. 